The present invention relates generally to synthetic sports fields and more specifically to a modular indoor/outdoor synthetic sports turf.
Synthetic grass sports surfaces are well known. These surfaces are becoming increasingly popular as replacements for natural grass surfaces in stadiums, playgrounds, golf driving ranges, and other facilities where natural grass is typically utilized. The synthetic grass surfaces stand up to wear much better than the natural grass surfaces, do not require as much maintenance, and can be used in partially or fully enclosed stadiums where natural grass cannot typically be grown.
Most synthetic grass surfaces comprise rows of strips or ribbons of synthetic grass-like material, extending vertically from a backing mat with particulate material infill in between the ribbons on the mat. One or more layers of aggregate material are typically introduced between the backing mat and on top of a smoothed and compacted subgrade. The surfaces are preferably crowned to promote water drainage.
The ribbons of synthetic grass-like material usually extend a short distance above the layer of particulate material and represent blades of grass. The length of these fibers is dictated by the end use of the playing surface. For example, football fields utilize fibers that are longer than golf driving range surfaces.
The particulate material usually comprises sand, as shown by way of example in U.S. Pat. No. 3,995,079 and U.S. Pat. No. 4,389,435, both to Haas, Jr. The particulate matter can also comprise a mixture of sand and other materials, including rubber infill, as shown, for example, in U.S. Pat. No. 6,338,885 to Prevost. In these systems, the rubber infill and sand together provide resiliency to the synthetic grass surfaces. In addition, the sand particles add weight to hold down the backing material, thus helping to ensure that the strips of synthetic grass do not move or shift during play.
While the growth of synthetic grass surfaces has grown exponentially over the past quarter century, the technology used in forming the grass surfaces and laying the synthetic fields is still relatively new. For example, there is no current technology available for easily installing and subsequently removing the synthetic grass surfaces for indoor multipurpose stadiums that utilize the arenas for substantially different sporting events and concerts.
To install a typical indoor synthetic grass field, strips of synthetic turf are unrolled and aligned on the floor or onto a level subgrade previously installed over the floor. Each strip of turf is then sewn together to the next adjacent strip(s) to ensure that no gaps exist between the strips. A layer of infill is then introduced over the strips of turf, leveled and groomed. This process is time consuming and labor intensive.
To remove the field, the infill must first be removed. The process of removing the infill is tedious and inefficient, as millions of small particles of sand and/or rubber are difficult to pick up and remove. Next, the strips must be removed one at a time. To accomplish this, the seams must be cut or otherwise un-sewn. The strips must then be re-rolled and removed. Finally, if a level subgrade is added over the flooring, it must also be removed. As such, the indoor venue may not be ready for other events for several days.
Because of the time and expense in removing these indoor synthetic fields, it is more likely that the fields will remain in place while other events within the venue are staged. For example, in late 2003, Ford Field in Detroit, Mich. staged a collegiate basketball game between Michigan State University and the University of Kentucky. In this game, a basketball floor was installed over the synthetic grass surface, rather than removing the grass surface, a process that was potentially damaging to the underlying grass surface.
It is thus highly desirable to produce a synthetic grass surface having desired playability while being easy to install and remove that is especially ideal for use in indoor multipurpose sporting arenas.